High frequency probe card for probing photoelectric device

ABSTRACT

A high frequency probe card for probing a photoelectric device includes a substrate having a first opening and at least one first through hole, an interposing plate disposed on the substrate and having a second opening and at least one second through hole, a circuit board disposed on the interposing plate and having a third opening and at least one third through hole, and a probe module mounted to the substrate and having at least one ground probe and at least one high-frequency impedance matching probe having a signal transmitting structure and a grounding structure passing through the at least one first, second and third through holes and being electrically connected with a signal pad and a ground pad of the circuit board, respectively. The first, second and third openings are communicated with each other for light transmission.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Taiwan Patent Application No.102126339 filed on Jul. 23, 2013, the entire content of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to probe cards for probing devices undertest and more particularly, to a high frequency probe card for probing aphotoelectric device.

2. Description of the Related Art

In a task of testing semiconductor chip, the tester is indirectly andelectrically connected with a device under test (hereinafter referred toas ‘DUT’) through a probe card. The conventional probe card is generallycomposed of a circuit board and a plurality of probes. On the topsurface of the circuit board, a plurality of top contact pads for beingelectrically contacted by the tester are provided. The bottom surface ofthe circuit board is provided with bottom contact pads electricallyconnected with the top contact pads. The probes are respectivelysoldered to the bottom contact pads and arranged in a patterncorresponding to that of contacts of the DUT. When the probes contactthe corresponding contacts of the DUT respectively, they can transmitthe testing signals from the tester to the DUT for enabling the testerto detect and measure the electric characteristics of the DUT.

The probe card designed for testing image sensing devices, such as CMOSimage sensors, or other photoelectric devices further comprises anopening in which a lens module is mounted. When the probe card probesthe DUT, testing light can reach on the DUT through the lens module.After the DUT receives the testing light, the DUT converts the testinglight to electric signal, which is transmitted to the tester through theprobe card for enabling the tester to analyze characteristics of theDUT.

Nowadays, the lens modules used in electronic devices usually have asmaller size with a larger numbers of pixels; therefore, thephotoelectric device usually works under a high frequency condition. Inorder to transmit the high frequency testing signals effectively, theprobe card must have a certain impedance matching with those of thetester and the DUT so as to accurately reflect the test result. However,the commercially available probe cards for probing photoelectric devicescannot fulfill the requirement of high frequency testing at present.

In another aspect, the top contact pads of the circuit board of theprobe card are electrically connected with the bottom contact padsthrough an internal circuit layout of the circuit board. Therefore, itis difficult in manufacturing such a circuit board, and the signals maynot be smoothly transmitted due to the fact that the internal circuitlayout may have many bends and curves. Further, if the internal circuitlayout of the circuit board is configured having a high frequency signaltrace accompanying a grounding trace for impedance matching, the circuitboard will be more difficultly manufactured.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances inview. It is an objective of the present invention to provide a highfrequency probe card for probing a photoelectric device, which canfulfil requirement of high frequency testing and transmit the testingsignal smoothly, and can be easily made.

To achieve the above-mentioned objective, the high frequency probe cardfor probing a photoelectric device provided by the present inventioncomprises a substrate, an interposing plate, a circuit board and a probemodule. The substrate has a first opening for light transmission, and atleast one first through hole. The interposing plate is disposed on thesubstrate and provided with a second opening communicated with the firstopening for light transmission, and at least one second through holecommunicated with the at least one first through hole. The circuit boardhas a top surface, a bottom surface disposed on the interposing plate,at least one ground pad and at least one signal pad arranged on the topsurface, a third opening penetrating through the top and bottom surfacesand being communicated with the second opening for light transmission,and at least one third through hole penetrating through the top andbottom surfaces and being communicated with the at least one secondthrough hole. The probe module is mounted to the substrate and providedwith at least one ground probe and at least one high-frequency impedancematching probe. The high-frequency impedance matching probe has a signaltransmitting structure and a grounding structure, which pass through theat least one first, second and third through holes. The signaltransmitting structure and the grounding structure are electricallyconnected with the signal pad and the ground pad of the circuit board,respectively.

By means of the above-mentioned design, the first, second and thirdopenings can combinedly form a space that accommodates a lens module,through which a testing light may reach on the DUT. Therefore, the probecard of the present invention can be used to inspect a photoelectricdevice. The high-frequency impedance matching probe of the probe cardmay have a certain impedance matching with those of the tester and theDUT, such that the high frequency probe card of the present inventioncan fulfil requirement of high frequency testing. Further, thehigh-frequency impedance matching probe penetrates through thesubstrate, the interposing plate and the circuit board and has a signaltransmitting structure electrically connected with the signal pad on thetop surface of the circuit board. The signal pads are formed by acircuit layout on the top surface of the circuit board for beingelectrically contacted by testing contacts of a tester; therefore, thetesting signal needs not to be transmitted through the internal circuitlayout of the circuit board. In this way, the testing signal can betransmitted smoothly and the circuit board can be more easily made.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given herein below and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a cross-sectional view of a high frequency probe card forprobing a photoelectric device according to a first embodiment of thepresent invention, in which high-frequency impedance matching probes ofa first kind and a device under test are shown;

FIG. 2 is another cross-sectional view of the high frequency probe cardof the first embodiment of the present invention, in which ground probesof a first kind is shown;

FIG. 3 is a schematic perspective view showing the arrangement of asubstrate, three probe modules and three fixing members of the highfrequency probe card;

FIG. 4 is a schematic perspective view showing the probe module havingthe high-frequency impedance matching probes of the first kind and theground probe of the first kind;

FIGS. 5 and 6 are schematic perspective views showing two alternateforms of the substrate of the high frequency probe card of the presentinvention;

FIG. 7 is a schematic perspective view showing a probe module havinghigh-frequency impedance matching probes of a second kind and a groundprobe of a second kind;

FIGS. 8 and 9 are schematic perspective views showing two alternatearrangements of the high-frequency impedance matching probe and theground probe connected to the high-frequency impedance matching probe ina one-to-one manner;

FIG. 10 is a cross-sectional view of the high frequency probe card ofthe present invention, showing that the circuit board has firstconductive through holes in which a ground probe of the third kind and aregular probe are respectively inserted;

FIG. 11 is a cross-sectional view of the high frequency probe card ofthe present invention, showing two alternate arrangements of conductorsof the probe module having the high-frequency impedance matching probesof the first kind;

FIG. 12 is a cross-sectional view of the high frequency probe card ofthe present invention, showing another arrangement of the conductor ofthe probe module having the high-frequency impedance matching probes ofthe first kind and a third kind;

FIG. 13 is a schematic perspective view showing a probe module havingthe high-frequency impedance matching probes of the third kind and theground probe of the first kind;

FIG. 14 is a cross-sectional view of the high frequency probe card ofthe present invention, showing two alternate arrangements of conductorsof the probe module having the high-frequency impedance matching probesof the third kind;

FIG. 15 is a cross-sectional view of the high frequency probe card ofthe present invention, in which high-frequency impedance matching probesof a fourth kind are shown; and

FIG. 16 is a cross-sectional view of the high frequency probe card ofthe present invention, showing that the circuit board has secondconductive through holes in which the high-frequency impedance matchingprobes of the third and fourth kinds are respectively inserted.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numerals are used in thedrawings and the description to refer to the same or like parts.

FIGS. 1-2 are schematic cross-sectional views of a high frequency probecard for probing a photoelectric device according to a first embodimentof the present invention. As shown in FIGS. 1-4, the high frequencyprobe card 10 mainly comprises a substrate 20, an interposing plate 30,a circuit board 40, and three probe modules 50. The number of the probemodules 50 is not limited to three. One or more probe modules 50 can beused in accordance to actual need. In other words, the high frequencyprobe card 10 of the present invention may include at least one probemodule 50. FIG. 3 is a schematic perspective view showing that eachprobe module 50 is fixedly mounted to the substrate 20 through a fixingmember 60. FIG. 4 is a schematic perspective view of one probe module50.

The probe module 50 includes a ground probe 51A and a plurality ofhigh-frequency impedance matching probes 52A. The number of thehigh-frequency impedance matching probes 52A may depend on actual need.In other words, the probe module 50 may include at least one groundprobe 51A and at least one high-frequency impedance matching probe 52A.Each high-frequency impedance matching probe 52A is mainly composed of aneedle 53 and a lead wire 54 configured in a way that the needle 53 andthe lead wire 54 are electrically insulated from each other. Each of theground probe 51A and the needle 53 is an N-type bare needle having anelongated body 512 or 532, a curved connection portion 514 or 534 at anend of the elongated body 512 or 532, and a detecting portion 516, 536suspended from the other end of the elongated body 512 or 532. In thisembodiment, the needle 53 and the lead wire 54 are electricallyinsulated from each other by an insulation member 55 encapsulating thelead wire 54. In fact, the lead wire 54 and the insulation member 55combinedly form a so-called enamelled wire. However, the way ofinsulating the needle 53 from the lead wire 54 is not limited to thedisclosure in this embodiment. For example, the needle 53 may be coatedwith a layer of insulation member.

The substrate 20 has a first opening 21 for light transmission, and aplurality of first through holes 22 arranged around the periphery of thefirst opening 21 for insertion of the probes therethrough. Each firstthrough hole 22 may be configured as an elongated through hole 22A, asshown in FIG. 5, such that the ground probe 51A and the high-frequencyimpedance matching probes 52A of a same probe module 50 can be insertedthrough a single first through hole 22A. It will be appreciated that thethree elongated first through holes 22A shown in FIG. 5 may be designedto be communicated with each other so as to form a single U-shaped firstthrough hole. As shown in FIG. 6, the first through holes 22 areconfigured as round through holes 22B provided in a groove 23. The roundthrough holes 22B each have a relatively smaller diameter for insertionof a single ground probe 51A or a single high-frequency impedancematching probe 52A. It is to be understood that the substrate 20 may bedesigned having the first through holes 22B without any of the grooves23.

The interposing plate 30 is mounted on the substrate 20 and providedwith a second opening 31 communicated with the first opening 21 forlight transmission, and at least one second through hole 32 communicatedwith the first through hole 22 for the passing of the probe(s). Thestructure of the second through hole 32 may be identical or similar tothat of the first through hole 22. That is, the second through hole 32may be an elongated through hole, a U-shaped through hole or a smallthrough hole that allows passing of one single probe only.

The circuit board 40 has a top surface 41, a bottom surface 42 mountedon the interposing plate 30, a plurality of ground pads 43 and aplurality of signal pads 44 arranged on the top surface 41, and a thirdopening 45 and a plurality of third through holes 46A each penetratingthrough the top surface 44 and the bottom surface 42. It will beappreciated that the numbers of the ground pads 43 and the signal pads44 are not specially limited. In other words, one or more ground pads 43and signal pads 44 may be provided on the top surface 41 of the circuitboard 40 in accordance with actual need. The third opening 45 iscommunicated with the second opening 31 for light transmission. Thethird through hole 46A is communicated with the second through hole 32,and the third through hole 46A is a small through hole that allowspassing of one single probe only. It is to be understood that the numberof the third through holes is not specially limited and may depend onthe number of the probes that pass through the circuit board 40.

As shown in FIG. 1, the first opening 21, the second opening 31 and thethird opening 41 combinedly form a space for accommodating a lens module12, through which a testing light may reach on the DUT 14. Therefore,the probe card 10 of the present invention can be used to inspectphotoelectric device. Specifically speaking, the lens module 12 isscrewingly threaded to a wall of the second opening 31, such that theposition of the lens module 12 can be adjusted. For high-frequencyimpedance matching probe 52A, the body 532 of the needle 53 and the leadwire 54 are spacedly abutted together and inserted through the firstthrough hole 22, the second through hole 32 and the third through hole46A in such a way that the connection portion 534 of the needle 53 iselectrically connected with the signal pad 44 by soldering and the leadwire 54 is electrically connected with the ground pad 43 by soldering.In this way, the needle 53 of the high-frequency impedance matchingprobe 52A forms a signal transmitting structure electrically connectedwith the signal pad 44, and the lead wire 54 of the high-frequencyimpedance matching probe 52A forms a grounding structure electricallyconnected with the ground pad 43. As shown in FIG. 2, each ground probe51A is inserted through the first through hole 22, the second throughhole 32 and the third through hole 46A and soldered to one ground pad43.

The signal pads 41 and the ground pads 43 are parts of a circuit layouton the top surface 41 of the circuit board 40 for being electricallycontacted by testing contacts of a tester (not shown in the drawings)for enabling the detecting portion 536 of the needle 53 and thedetecting portion 516 of the ground probe 51A to respectively transmittesting signal and ground voltage between the tester and the DUT 14. Theneedle 53 of the high-frequency impedance matching probe 52A may have acertain impedance matching with those of the tester and the DUT 14because the needle 53 is accompanied with the grounded lead wire 54,such that the requirement of high frequency testing can be fulfilled.Further, the testing signal needs not to be transmitted through theinternal circuit layout of the circuit board 40; therefore, the testingsignal can be transmitted smoothly and the circuit board 40 can be moreeasily made.

As shown in FIG. 4, the probe module 50 may further include a conductor56. By means of one or more insulated members, such as insulatedadhesive or insulated sheets, the needles 53 are insulated from theconductor 56. The lead wires 54 and the ground probe 51A areelectrically connected together via the conductor 56. Therefore, thelead wires 54 and the ground probe 51A are all grounded as long as oneof them is soldered to one of the ground pads 43. Under thiscircumstance, the probe module 50 may adopt a short ground probe, suchas the ground probe 51B shown in FIG. 7, which is shorter than theground probe 51A disclosed in FIG. 4 and doesn't penetrate through thesubstrate 20, the interposing plate 30 and the circuit board 40.Further, the probe module 50 may also adopt the high-frequency impedancematching probes 52B shown in FIG. 7. Compared to the high-frequencyimpedance matching probe 52A, the high-frequency impedance matchingprobe 52B further comprises an insulation sleeve 57 sleeved onto theneedle 53 and the lead wire 54 for ensuring that the needle 53 can bekept at a constant distance from the lead wire 54.

It is worth mentioning that the probe module is not limited to beconfigured having the one-to-many construction that one ground probe isin association with a plurality of high-frequency impedance matchingprobes. For example, the probe module may be configured having groundprobes corresponding in number to high-frequency impedance matchingprobes in a one-to-one construction that one ground probe is inassociation with one high-frequency impedance matching probe. As shownin FIGS. 8 and 9, one single high-frequency impedance matching probe 52Bis associated with one single ground probe 51A or 51B. In this case, anend of the lead wire 54 is directly connected with the ground probe 51Aor 51B, such that the electric connection between the lead wire 54 andthe ground probe 51A or 51B can be realized, and the other end of thelead wire 54 passes through the substrate 20, the interposing plate 30and the circuit board 40 and is electrically connected with a ground pad43 on the top surface 41 of the circuit board 40.

As shown in FIGS. 1 and 2, each third through hole 46A of the circuitboard 40, which is adapted for passing of the ground probe 51A or thehigh-frequency impedance matching probe 52A, has a bare hole wallwithout any coating of conductive material. That is, the third throughholes 46A are insulated through holes. However, the third through holes46A of the circuit board 40 may include at least one first conductivethrough hole 46B as shown in FIG. 10. The first conductive through hole46B has a hole wall provided with electrically conductive material 462,and an end of the first conductive through hole 46B is provided with orelectrically connected through a circuit layout with a ground pad 43 ora signal pad 44 that is electrically connected with the electricallyconductive material 462. As shown in left side of FIG. 10, a groundprobe 51C is inserted in one first conductive through hole 46B andfirmly contacted with the electrically conductive material 462, suchthat the ground probe 51C is electrically connected with the ground pad43. As shown in right side of FIG. 10, a regular probe 16 fortransmitting low or intermediate frequency signal is inserted in onefirst conductive through hole 46B and electrically connected with thesignal pad 44 via the electrically conductive material 462.

In the above-mentioned probe nodules 50, the needles 53 and the leadwires 54 of the high-frequency impedance matching probes are arranged onthe same lateral side of the conductor 56, and the conductor 56 isdisposed in the first through hole 22 and corresponds in location to thebody 532 of the needle 53. However, this arrangement can have variousmodifications. For example, as shown in left side of FIG. 11, theconductor 56 is arranged between the needle 53 and the lead wire 54.Further, as shown in right side of FIG. 11, the conductor 56 is arrangedon the detecting portion 536 of the needle 53 and located outside thesubstrate 20. Furthermore, the conductor 56 can be arranged in thesecond through hole 32 of the interposing plate 30. As shown in leftside of FIG. 12, the conductor 56 is arranged in the groove 23 of thesubstrate 20. In this case, the short ground probe 51B, which doesn'tpenetrate through the substrate 20, the interposing plate 30 and thecircuit board 40, is used and electrically mounted to the conductor 56.

In the embodiment disclosed in FIGS. 1 and 2, the fixing members 60 forfixedly fastening the probes 51A and 52A to the substrate 20 are madeof, but not limited to, engineering plastics, Bakelite or ceramicmaterial. The fixing member 60 has through holes 62 for insertion of theprobes 51A and 52A. In assembly, the probes 51A and 52A are insertedthrough the through holes 62 and then fixed with the fixing member 60via adhesive. Thereafter, the fixing member 60 is mounted to thesubstrate 20, and then an adhesive 18, such as epoxy resin and the like,is applied to conjunction between the probes 51A and 52A and the fixingmember 60, the probes 51A and 52A and the substrate 20, and/or thesubstrate 20 and the fixing member 60 so as to firmly fasten the fixingmember 60 and the probes 51A and 52A to the substrate 20. It is to beunderstood that structure of the fixing member 60 and the arrangement ofthe adhesive 18 may have various modifications. For example, as shown inleft side of FIG. 11, the fixing member 60 is configured without throughholes. The fixing member 60 is inserted between the probes and thesubstrate 20 and firmly held in position by the adhesive 18. Further, asshown in right side of FIG. 11, the adhesive 18 is used to encapsulate apart of the detecting portion 536 of the needle 53 and the conductor 56so as to secure the fastening relationship among the fixing member 60,probes and the conductor 56. It is to be further mentioned that thefixing member 60 may not be received in the groove 23. Instead, thefixing member 60 can be directly mounted on the surface of the substrate20 that corresponds in location to the groove 23 or on any properlocation of the surface of the substrate 20.

The probe module 50 may adopt the high-frequency impedance matchingprobes 52C shown in FIG. 13 and right side of FIG. 12. Thehigh-frequency impedance matching probe 52C includes a needle 53 asdescribed above, an insulation member 58 encapsulating around the needle53, and a grounding conductive member 59 partially or completelyencapsulating around the insulation member 58, such that the needle 53and the grounding conductive member 59 form the signal transmittingstructure and grounding structure of the high-frequency impedancematching probe 52C, respectively. The grounding conductive member 59 ofthe high-frequency impedance matching probe 52C is electricallyconnected with the ground probe, such as but not limited to the groundprobe 51A shown in FIG. 13, via the conductor 56. The conductor 56 maybe fixedly mounted in the groove 23 of the substrate 20 as shown in leftside of FIG. 14. Alternatively, the conductor 56 may be insulatedlymounted on the detecting portion 536 of the needle 53, as shown in rightside of FIG. 14, and electrically connected with the groundingconductive member 59 via a lead wire 19.

The probe module 50 may also adopt the high-frequency impedance matchingprobes 70 shown in FIG. 15. The high-frequency impedance matching probe70 is composed of a needle 71 and a coaxial wire 72. The needle 71mainly includes an arm-like detecting portion for probing the DUT, andis electrically connected with the signal pad 44 via the coaxial wire72. Specifically speaking, the coaxial wire 72 is composed of a core722, an insulation member 724 encapsulating around the core 722, and agrounding conductive member 726 encapsulating around the insulationmember 724. The needle 71 is connected with the core 722 of the coaxialwire 72, such that the needle 71 and the core 722 combinedly form thesignal transmitting structure of the high-frequency impedance matchingprobe 70. On the other hand, the grounding structure of thehigh-frequency impedance matching probe 70 is formed by the groundingconductive member 726 of the coaxial wire 72. As shown in right side ofFIG. 15, the grounding conductive member 726 is electrically connectedwith the conductor 56 that is electrically connected with the groundprobe (not shown) via a lead wire 19, such that the grounding conductivemember 726 is indirectly and electrically connected with the groundprobe. The conductor 56 is insulatedly mounted on the needle 71.

In the embodiments shown in FIGS. 12, 14 and 15, the high-frequencyimpedance matching probes 52C and 70 are respectively inserted throughthe insulated through holes 46A of the circuit boards 40 and thegrounding conductive members 59 and 726 are respectively andelectrically connected with the ground pads 43 via lead wires 19.However, the third through holes of the circuit board 40 may include atleast one second conductive through hole 46C as shown in FIG. 16. Thesecond conductive through hole 46C has a hole wall provided withelectrically conductive material 462, and an end of the secondconductive through hole 46C is provided with or electrically connectedthrough a circuit layout with a ground pad 43 that is electricallyconnected with the electrically conductive material 462. As shown inright side of FIG. 16, a high-frequency impedance matching probe 52C isinserted through the second conductive through hole 46C in a way thatthe grounding conductive member 59 of the high-frequency impedancematching probe 52C is firmly contacted with the electrically conductivematerial 462, such that the grounding conductive member 59 iselectrically connected with the ground pad 43. As shown in left side ofFIG. 16, a high-frequency impedance matching probe 70 is insertedthrough the second conductive through hole 46C is such a way that thegrounding conductive member 726 of the high-frequency impedance matchingprobe 70 is electrically connected with the ground pad 43 via theelectrically conductive material 462. Because the diameter of thehigh-frequency impedance matching probe 52C or 70 is greater that thediameter of bare ground probe or regular probe for transmitting low orintermediate frequency signal, the second conductive through hole 46Chas a diameter greater than that of the first conductive through hole46B adapted for insertion of the ground probe or the regular probe. Inorder to prevent the adverse affection to the arrangement of thegrounding conductive member 59 due to the bending treatment of thehigh-frequency impedance matching probe 52C after the high-frequencyimpedance matching probe 52C passes through the third through hole 46Aor 46C, the part of the grounding conductive member 59 above the topsurface of the circuit board 40 as disclosed in right side of FIG. 12,left and right sides of FIG. 14 and right side of FIG. 16 may bearranged on the top surface of the circuit board 40 around the thirdthrough hole 46A or 46C, e.g. circling the third through hole 46A or46C; therefore, the grounding conductive member 59 can be indirectly andelectrically connected with the ground pad 43 on the top surface of thecircuit board 40 via the lead wire 19 or directly and electricallyconnected with the ground pad 43 on the top surface of the circuit board40 after the high-frequency impedance matching probe 52C passes throughthe third through hole 46A or 46C.

As indicated above, the high frequency probe card 10 provided by thepresent invention has the first, second and third openings 21, 31 and 45for accommodation of the lens module 12 and for light transmission, sothat the high frequency probe card 10 can be used to inspectphotoelectric device. The high frequency probe card 10 may adopt anykind of high-frequency impedance matching probes 52A, 52B, 52C and 70which have been detailedly illustrated in the preceding paragraphs forimpedance matching with the tester and device under test; therefore, thehigh frequency probe card of the present invention can fulfill therequirement of high frequency testing. Further, the high-frequencyimpedance matching probes 52A, 52B, 52C and 70 are arranged to penetratethrough the substrate 20, the interposing plate 30 and the circuit board40 and electrically connected with the signal pads 44 on the top surfaceof the circuit board 40; therefore, the testing signal needs not to betransmitted through the internal circuit layout of the circuit board 40,so that the testing signal can be transmitted smoothly and the circuitboard 40 can be more easily made. Furthermore, one of the third throughholes 46A, 46B or 46C provided by the circuit board 40 is associatedwith one of the high-frequency impedance matching probes 52A, 52B, 52Cor 70. That is, one third through hole is inserted with onehigh-frequency impedance matching probe only. Therefore, thehigh-frequency impedance matching probes can be well positioned andfixed and every high frequency probe card thus made may have consistentarrangement of the high-frequency impedance matching probes.

Although particular embodiments of the invention have been described indetail for purposes of illustration, various modifications andenhancements may be made without departing from the spirit and scope ofthe invention. Accordingly, the invention is not to be limited except asby the appended claims.

What is claimed is:
 1. A high frequency probe card for probing aphotoelectric device, the high frequency probe card comprising: asubstrate having a first opening for light transmission, and at leastone first through hole; an interposing plate disposed on the substrateand provided with a second opening communicated with the first openingfor light transmission, and at least one second through holecommunicated with the at least one first through hole; a circuit boardhaving a top surface, a bottom surface disposed on the interposingplate, at least one ground pad and at least one signal pad arranged onthe top surface, a third opening penetrating through the top and bottomsurfaces and being communicated with the second opening for lighttransmission, and at least one third through hole penetrating throughthe top and bottom surfaces and being communicated with the at least onesecond through hole; and a probe module mounted to the substrate andprovided with at least one ground probe and at least one high-frequencyimpedance matching probe having a signal transmitting structure and agrounding structure, the signal transmitting structure and the groundingstructure passing through the at least one first, second and thirdthrough holes and being electrically connected with the signal pad andthe ground pad of the circuit board, respectively, wherein the probemodule comprises a conductor, the signal transmitting structure isinsulated from the conductor by an insulated member, and the groundingstructure and the at least one ground probe are electrically connectedtogether by the conductor.
 2. The high frequency probe card as claimedin claim 1, wherein the circuit board comprises a plurality of saidthird though holes and the probe module comprises a plurality of saidhigh-frequency impedance matching probes each passing through one ofsaid third through holes.
 3. The high frequency probe card as claimed inclaim 1, wherein the circuit board comprises a plurality of said thirdthough holes; the at least one ground probe and the at least onehigh-frequency impedance matching probe each pass through one of saidthird through holes.
 4. The high frequency probe card as claimed inclaim 3, wherein the third through holes comprise a conductive throughhole having a hole wall provided with an electrically conductivematerial; the ground probe is inserted in the conductive through holeand electrically connected with the ground pad through the electricallyconductive material of the conductive through hole.
 5. The highfrequency probe card as claimed in claim 1, wherein the high-frequencyimpedance matching probe comprises a needle and a lead wire configuredin a way that the needle and the lead wire are electrically insulatedfrom each other; the needle forms the signal transmitting structure ofthe high-frequency impedance matching probe, and the lead wire forms thegrounding structure of the high-frequency impedance matching probe. 6.The high frequency probe card as claimed in claim 5, wherein the atleast one third through hole of the circuit board comprises anelectrically insulated through hole through which the high-frequencyimpedance matching probe is inserted.
 7. The high frequency probe cardas claimed in claim 1, wherein the high-frequency impedance matchingprobe comprises a needle, an insulation member encapsulating the needle,and a grounding conductive member having at least a part encapsulatingthe insulation member; the needle forms the signal transmittingstructure of the high-frequency impedance matching probe, and thegrounding conductive member forms the grounding structure of thehigh-frequency impedance matching probe.
 8. The high frequency probecard as claimed in claim 7, wherein the at least one third through holecomprises a conductive through hole having a hole wall provided with anelectrically conductive material; the high-frequency impedance matchingprobe is inserted in the conductive through hole in a way that thegrounding conductive member is electrically connected with the groundpad through the electrically conductive material of the conductivethrough hole.
 9. The high frequency probe card as claimed in claim 7,wherein the at least one third through hole comprises a first conductivethrough hole having a hole wall provided with an electrically conductivematerial, and a second conductive through hole having a hole wallprovided with an electrically conductive material; the second conductivethrough hole has a diameter larger than that of the first conductivethrough hole; the high-frequency impedance matching probe is inserted inthe second conductive through hole in a way that the groundingconductive member is electrically connected with the ground pad throughthe electrically conductive material of the second conductive throughhole.
 10. The high frequency probe card as claimed in claim 1, whereinthe high-frequency impedance matching probe comprises a needle and acoaxial wire having a core, an insulation member encapsulating the core,and a grounding conductive member encapsulating the insulation member;the needle and the core of the coaxial wire are connected with eachother to combinedly form the signal transmitting structure of thehigh-frequency impedance matching probe, and the grounding conductivemember of the coaxial wire forms the grounding structure of thehigh-frequency impedance matching probe.
 11. The high frequency probecard as claimed in claim 10, wherein the at least one third through holecomprises a conductive through hole having a hole wall provided with anelectrically conductive material; the high-frequency impedance matchingprobe is inserted in the conductive through hole in a way that thegrounding conductive member of the coaxial wire is electricallyconnected with the ground pad through the electrically conductivematerial of the conductive through hole.
 12. The high frequency probecard as claimed in claim 10, wherein the at least one third through holecomprises a first conductive through hole having a hole wall providedwith an electrically conductive material, and a second conductivethrough hole having a hole wall provided with an electrically conductivematerial; the second conductive through hole has a diameter larger thanthat of the first conductive through hole; the high-frequency impedancematching probe is inserted in the second conductive through hole in away that the grounding conductive member of the coaxial wire iselectrically connected with the ground pad through the electricallyconductive material of the second conductive through hole.
 13. The highfrequency probe card as claimed in claim 1, wherein the at least onesecond through hole of the interposing plate is an elongated throughhole.
 14. The high frequency probe card as claimed in claim 1, whereinthe at least one first through hole of the substrate is an elongatedthrough hole.
 15. The high frequency probe card as claimed in claim 1,wherein the substrate comprises a plurality of said first through holes;each of the ground probe and the high-frequency impedance matching probeis inserted through one of said first through holes.
 16. The highfrequency probe card as claimed in claim 1, wherein the groundingstructure of the high-frequency impedance matching probe has two endselectrically connected with the ground pad and the ground probe,respectively.
 17. The high frequency probe card as claimed in claim 1,further comprising a lens module screwingly threaded to a wall of thesecond opening of the interposing plate.